Plutonium result supports theory of shape isomers

Over the past few years evidence has grown for the existence of a double‐humped fission barrier in many different nuclei. These nuclei when caught between the two humps would then exist in isomeric states with lifetimes that were very long considering their excitation. The phenomenon goes by the name of “shape isomerism.” Now a Munich group has reported (at the European Conference on Nuclear Physics in Aix en Provence, at the end of June) that they have found a rotational band associated with the second minimum in the fission barrier, thus providing strong support for the idea of shape isomerism. The group consists of Hans J. Specht and J. Weber of the University of Munich and E. Konecny and D. Heunemann of the Munich Technical University.